Rule-based network identifier mapping

ABSTRACT

One embodiment of the present invention provides a switch. The switch includes a storage device, a rule management module, a network identifier module, and a packet processor. During operation, the rule management module stores, in the storage device, a first mapping that maps a virtual network identifier of a tunnel to a rule for classifying traffic. The virtual network identifier identifies a virtualized network associated with the tunnel. The network identifier module generates, for a virtualization manager of a virtual machine, a control packet comprising a representation of the first mapping for a respective local end device. The network identifier module then obtains, from a notification packet from the virtualization manger, a second mapping that maps the virtual network identifier to an identifier of the virtual machine and an identifier of the tunnel.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 62/414,585, Attorney Docket Number BRCD-3364.0.1.US.PSP, titled “Flow based VNI Mapping in VXLAN Gateway,” by inventor Ramakanth Josyula, filed 28 Oct. 2016, the disclosure of which is incorporated by reference herein.

The present disclosure is related to U.S. Pat. No. 8,867,552, application Ser. No. 13/087,239, Attorney Docket Number BRCD-3008.1.US.NP, titled “Virtual Cluster Switching,” by inventors Suresh Vobbilisetty and Dilip Chatwani, issued 21 Oct. 2014, filed 14 Apr. 2011, the disclosure of which is incorporated by reference herein.

BACKGROUND Field

The present disclosure relates to communication networks. More specifically, the present disclosure relates to a system and a method for facilitating rule-based network identifiers for separation of traffic in a tunnel.

Related Art

The exponential growth of the Internet has made it a popular delivery medium for a variety of applications running on physical and virtual devices. Such applications have brought with them an increasing demand for bandwidth. As a result, equipment vendors race to build larger and faster switches with versatile capabilities, such as efficient forwarding of multi-destination (e.g., broadcast, unknown unicast, and multicast) traffic. However, the capabilities of a switch cannot grow infinitely. It is limited by physical space, power consumption, and design complexity, to name a few factors. Furthermore, switches with higher capability are usually more complex and expensive. As a result, increasing efficiency in existing capabilities of a switch adds significant value proposition.

Typically, to expand a lower layer network across a higher layer network (e.g., an Ethernet network over an Internet Protocol (IP) network), a tunnel is established between two tunnel endpoints. If a device in a segment of a lower layer network cannot establish a tunnel, a tunnel gateway is used. A tunnel gateway can originate or terminate tunnels for the devices in that network segment. The tunnel gateway can be a distributed (or virtual) tunnel endpoint, which can be associated with a plurality of switches operating as a single, logical tunnel endpoint. A tunnel endpoint for a tunnel can originate or terminate tunnel forwarding for the tunnel.

While a distributed tunnel endpoint brings many desirable features in forwarding traffic via tunnels, some issues remain unsolved in facilitating the separation of traffic via a tunnel.

SUMMARY

One embodiment of the present invention provides a switch. The switch includes a storage device, a rule management module, a network identifier module, and a packet processor. During operation, the rule management module stores, in the storage device, a first mapping that maps a virtual network identifier of a tunnel to a rule for classifying traffic. The virtual network identifier identifies a virtualized network associated with the tunnel. The network identifier module generates, for a virtualization manager of a virtual machine, a control packet comprising a representation of the first mapping for a respective local end device. The network identifier module then obtains, from a notification packet from the virtualization manger, a second mapping that maps the virtual network identifier to an identifier of the virtual machine and an identifier of the tunnel.

In a variation on this embodiment, the packet processor encapsulates a packet destined to the virtual machine with an encapsulation header and incorporates the virtual network identifier in the encapsulation header based on the second mapping.

In a variation on this embodiment, the switch also includes a tunnel management module, which operates the switch as a tunnel endpoint for the tunnel. The switch is then associated with an Internet Protocol (IP) address assigned to the tunnel endpoint.

In a further variation, the tunnel endpoint operates based on a tunneling protocol, which can be one of: virtual extensible local area network (LAN) (VXLAN), generic routing encapsulation (GRE), network virtualization using GRE (NVGRE), layer-2 tunneling protocol (L2TP), and multi-protocol label switching (MPLS).

In a variation on this embodiment, the rule is based on one or more of: a flow definition, a flow identifier assigned to a flow defined by a flow definition, a media access control (MAC) address, an IP address, an IP subnet, a customer VLAN tag, a service VLAN, and a global VLAN tag.

In a further variation, the flow definition identifies a packet belonging to a flow. The flow definition can be based on one or more of: a source MAC address of the packet, a destination MAC address of the packet, a source IP address of the packet, a destination IP address of the packet, an ingress port of the tunnel endpoint, and a transport protocol port.

In a variation on this embodiment, the switch is a member of a network of interconnected switches, which is identified based on a fabric identifier. The network of interconnected switches operates as a tunnel endpoint for the tunnel.

In a variation on this embodiment, the first mapping further comprises a VLAN identifier and a sequence number of the rule.

In a variation on this embodiment, the virtual network identifier is a VXLAN network identifier (VNI).

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A illustrates an exemplary tunnel endpoint with rule-based network identifier mapping support for a tunnel, in accordance with an embodiment of the present invention.

FIG. 1B illustrates an exemplary media access control (MAC) address table facilitating rule-based network identifier mapping for a tunnel, in accordance with an embodiment of the present invention.

FIG. 1C illustrates an exemplary rule mapping table facilitating rule-based network identifier mapping for a tunnel, in accordance with an embodiment of the present invention.

FIG. 1D illustrates an exemplary network identifier allocation table facilitating rule-based network identifier mapping for a tunnel, in accordance with an embodiment of the present invention.

FIG. 1E illustrates an exemplary MAC mapping table facilitating rule-based network identifier mapping, in accordance with an embodiment of the present invention.

FIG. 2 illustrates an exemplary network of interconnected switched operating as a tunnel endpoint with rule-based network identifier mapping support, in accordance with an embodiment of the present invention.

FIG. 3A presents a flowchart illustrating an exemplary process of a tunnel endpoint allocating a network identifier to a rule, in accordance with an embodiment of the present invention.

FIG. 3B presents a flowchart illustrating an exemplary process of a tunnel endpoint providing a network identifier allocation table to a virtualization manager, in accordance with an embodiment of the present invention.

FIG. 3C presents a flowchart illustrating an exemplary process of a tunnel endpoint processing a MAC mapping table received from a virtualization manager, in accordance with an embodiment of the present invention.

FIG. 4 presents a flowchart illustrating an exemplary process of a tunnel endpoint forwarding a packet, in accordance with an embodiment of the present invention.

FIG. 5 illustrates an exemplary tunnel endpoint with rule-based network identifier mapping support for a tunnel, in accordance with an embodiment of the present invention.

In the figures, like reference numerals refer to the same figure elements.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the claims.

Overview

In embodiments of the present invention, the problem of efficiently facilitating traffic separation in a tunnel is solved by (i) allocating a network identifier to a respective rule for a tunnel; and (ii) obtaining a mapping between a network identifier and a corresponding media access control (MAC) address from a virtualization manager. A tunnel endpoint can be a switch (or any computing device) capable of originating or terminating a tunnel encapsulation header. To forward a packet via the tunnel, the tunnel endpoint encapsulates the packet with an encapsulation header associated with a corresponding tunneling protocol. The source and destination addresses in the encapsulation header correspond to the tunnel endpoints of the tunnel. Examples of a tunneling protocol include, but are not limited to, virtual extensible LAN (VXLAN), generic routing encapsulation (GRE), network virtualization using GRE (NVGRE), layer-2 tunneling protocol (L2TP), and multi-protocol label switching (MPLS).

With existing technologies, different virtual local area networks (VLANs) are mapped to different corresponding network identifiers for a tunnel. A tunnel endpoint can include the network identifier in the encapsulation header associated with the tunnel. For example, if the tunneling protocol is VXLAN, the tunnel endpoint can be a virtual tunnel endpoint (VTEP), which maps a VXLAN network identifier (VNI) to a corresponding VLAN. As a result, packets belonging to different VLANs are separated in the tunnel. However, such allocation limits the traffic separation to only VLANs. Under such circumstances, other forms of traffic separation may not be available.

To solve this problem, a tunnel endpoint can allocate a network identifier based on a rule defined at the tunnel endpoint. A rule can be based on, but is not limited to, a flow definition, a flow identifier assigned to a flow defined by a flow definition, a source MAC address, a source Internet Protocol (IP) address, an IP subnet, a customer VLAN tag, a service VLAN tag, a global VLAN tag. A flow can be defined based on one or more of: a source MAC address, a destination MAC address, a source IP address, a destination IP address, an ingress port of the tunnel endpoint, and a transport protocol port (e.g., associated with a socket). The tunnel endpoint maps a respective network identifier to one or more corresponding MAC addresses based on the rule associated with the network identifier, and provides the mapping to a virtualization manager.

In some embodiments, a virtualization manager creates and manages a set of virtual machines running on one or more virtual machine monitors (VMMs) (e.g., hypervisors or Hyper-Vs). Upon receiving the mapping, the virtualization manager maps the virtual MAC addresses of these virtual machines to corresponding network identifiers and provides the mapping to the tunnel endpoint. The tunnel endpoint then updates the local MAC address table, based on the mapping. It should be noted that one or more entries of the MAC address table can also be populated based on layer-2 MAC address learning. Upon identifying a packet with a destination address associated with one of the virtual MAC addresses, the tunnel endpoint encapsulates the packet with a tunnel encapsulation header and sends the encapsulated packet via the tunnel. In some embodiments, the tunnel endpoint is in a distributed tunnel endpoint, which includes a plurality of tunnel endpoints operating based on virtual router redundancy protocol (VRRP).

In some embodiments, the tunnel endpoint can be a member switch of a network of interconnected switches (e.g., a fabric switch). In a fabric switch, any number of switches coupled in an arbitrary topology can be controlled as a single logical switch. The fabric switch can be an Ethernet fabric switch or a virtual cluster switch (VCS), which can operate as a single Ethernet switch. In some embodiments, a respective switch in the fabric switch is an Internet Protocol (IP) routing-capable switch (e.g., an IP router). In some further embodiments, a respective switch in the fabric switch is a Transparent Interconnection of Lots of Links (TRILL) routing bridge (RBridge).

It should be noted that a fabric switch is not the same as conventional switch stacking. In switch stacking, multiple switches are interconnected at a common location (often within the same rack), based on a particular topology, and manually configured in a particular way. These stacked switches typically share a common address, e.g., an IP address, so they can be addressed as a single switch externally. Furthermore, switch stacking requires a significant amount of manual configuration of the ports and inter-switch links. The need for manual configuration prohibits switch stacking from being a viable option in building a large-scale switching system. The topology restriction imposed by switch stacking also limits the number of switches that can be stacked. This is because it is very difficult, if not impossible, to design a stack topology that allows the overall switch bandwidth to scale adequately with the number of switch units.

In contrast, a fabric switch can include an arbitrary number of switches with individual addresses, can be based on an arbitrary physical topology, and does not require extensive manual configuration. The switches can reside in the same location, or be distributed over different locations. These features overcome the inherent limitations of switch stacking and make it possible to build a large “switch farm,” which can be treated as a single, logical switch. Due to the automatic configuration capabilities of the fabric switch, an individual physical switch can dynamically join or leave the fabric switch without disrupting services to the rest of the network.

Furthermore, the automatic and dynamic configurability of the fabric switch allows a network operator to build its switching system in a distributed and “pay-as-you-grow” fashion without sacrificing scalability. The fabric switch's ability to respond to changing network conditions makes it an ideal solution in a virtual computing environment, where network loads often change with time.

It should also be noted that a fabric switch is distinct from a VLAN. A fabric switch can accommodate a plurality of VLANs. A VLAN is typically identified by a VLAN tag. In contrast, the fabric switch is identified by a fabric identifier (e.g., a cluster identifier), which is assigned to the fabric switch. Since a fabric switch can be represented as a logical chassis, the fabric identifier can also be referred to as a logical chassis identifier. A respective member switch of the fabric switch is associated with the fabric identifier. In some embodiments, a fabric switch identifier is pre-assigned to a member switch. As a result, when the switch joins a fabric switch, other member switches identifies the switch to be a member switch of the fabric switch.

In this disclosure, the term “fabric switch” refers to a number of interconnected physical switches which can form a single, scalable network of switches. The member switches of the fabric switch can operate as individual switches. The member switches of the fabric switch can also operate as a single logical switch in the provision and control plane, the data plane, or both. “Fabric switch” should not be interpreted as limiting embodiments of the present invention to a plurality of switches operating as a single, logical switch. In this disclosure, the terms “fabric switch” and “fabric” are used interchangeably.

Although the present disclosure is presented using examples based on an encapsulation protocol, embodiments of the present invention are not limited to networks defined using one particular encapsulation protocol associated with a particular Open System Interconnection Reference Model (OSI reference model) layer. For example, embodiments of the present invention can also be applied to a multi-protocol label switching (MPLS) network. In this disclosure, the term “encapsulation” is used in a generic sense, and can refer to encapsulation in any networking layer, sub-layer, or a combination of networking layers.

The term “end host” can refer to any device external to a network (e.g., does not perform forwarding in that network). Examples of an end host include, but are not limited to, a physical or virtual machine, a conventional layer-2 switch, a layer-3 router, or any other type of network device. Additionally, an end host can be coupled to other switches or hosts further away from a layer-2 or layer-3 network. An end host can also be an aggregation point for a number of network devices to enter the network. An end host hosting one or more virtual machines can be referred to as a host machine. In this disclosure, the terms “end host” and “host machine” are used interchangeably.

The term “VLAN” is used in a generic sense, and can refer to any virtualized network. Any virtualized network comprising a segment of physical networking devices, software network resources, and network functionality can be can be referred to as a “VLAN.” “VLAN” should not be interpreted as limiting embodiments of the present invention to layer-2 networks. “VLAN” can be replaced by other terminologies referring to a virtualized network or network segment, such as “Virtual Private Network (VPN),” “Virtual Private LAN Service (VPLS),” or “Easy Virtual Network (EVN).”

The term “packet” refers to a group of bits that can be transported together across a network. “Packet” should not be interpreted as limiting embodiments of the present invention to layer-3 networks. “Packet” can be replaced by other terminologies referring to a group of bits, such as “frame,” “cell,” or “datagram.”

The term “switch” is used in a generic sense, and can refer to any standalone or fabric switch operating in any network layer. “Switch” can be a physical device or software running on a computing device. “Switch” should not be interpreted as limiting embodiments of the present invention to layer-2 networks. Any device that can forward traffic to an external device or another switch can be referred to as a “switch.” Examples of a “switch” include, but are not limited to, a layer-2 switch, a layer-3 router, a TRILL RBridge, or a fabric switch comprising a plurality of similar or heterogeneous smaller physical switches.

The term “edge port” refers to a port on a network which exchanges data frames with a device outside of the network (i.e., an edge port is not used for exchanging data frames with another member switch of a network). The term “inter-switch port” refers to a port which sends/receives data frames among member switches of the network. A link between inter-switch ports is referred to as an “inter-switch link.” The terms “interface” and “port” are used interchangeably.

The term “switch identifier” refers to a group of bits that can be used to identify a switch. Examples of a switch identifier include, but are not limited to, a media access control (MAC) address, an Internet Protocol (IP) address, an RBridge identifier, or a combination thereof. In this disclosure, “switch identifier” is used as a generic term, is not limited to any bit format, and can refer to any format that can identify a switch.

The term “tunnel” refers to a data communication where one or more networking protocols are encapsulated using another networking protocol. Although the present disclosure is presented using examples based on a layer-3 encapsulation of a layer-2 protocol, “tunnel” should not be interpreted as limiting embodiments of the present invention to layer-2 and layer-3 protocols. A “tunnel” can be established for and using any networking layer, sub-layer, or a combination of networking layers.

Network Architecture

FIG. 1A illustrates an exemplary tunnel endpoint with rule-based network identifier mapping support for a tunnel, in accordance with an embodiment of the present invention. A tunnel endpoint 104 facilitates rule-based network identifier mapping. In this example, switches 102 and 104 operate as tunnel endpoints for a tunnel 106 across network 130. Hence, switches 102 and 104 can also be referred to as tunnel endpoints 102 and 104, respectively. In some embodiments, tunnel endpoint 104 is in a distributed tunnel endpoint, which includes a plurality of tunnel endpoints operating based on VRRP (not shown in FIG. 1A). Network 130 can be a local area network, a wide area network, or the Internet. Tunnel 130 can be established based on a tunneling protocol. Examples of a tunneling protocol include, but are not limited to, VXLAN, GRE, NVGRE, L2TP, and MPLS.

Tunnel endpoint 104 is coupled to servers 132 and 134 via local ports 133 and 135, respectively. Servers 132 and 134 belong to a VLAN 110. Therefore, ports 133 and 135 are configured with VLAN 110. On the other hand, tunnel endpoint 102 is coupled to a host machine 120 running a VMM, which is a hypervisor 121 running a plurality of virtual machines 122, 123, 124, 125, 126, 127, 128, and 129. In some embodiments, a virtualization manager 108 creates and manages this set of virtual machines. Virtualization manager 108 can be a virtualization controller (e.g., VMware NSX controller) and in a cluster. In this example, each of these virtual machines belongs to VLAN 110. To extend VLAN 110 across network 130, a hypervisor can establish a VXLAN tunnel. However, servers 132 and 134 may not support VXLAN. Hence, tunnel endpoint 104 operates as a tunnel gateway for servers 132 and 134.

To forward a packet from server 132 (or 134) via tunnel 106, tunnel endpoint 104 encapsulates the packet with an encapsulation header associated with the tunneling protocol. The source and destination addresses of the encapsulation header correspond to the tunnel endpoints 104 and 102, respectively. The encapsulation header further includes a network identifier. With existing technologies, this network identifier distinguishes traffic belonging to different local networks, such as VLANs. To do so, different VLANs are mapped to different corresponding network identifiers. For example, if the tunneling protocol is VXLAN, tunnel endpoints 102 and 104 can operate as VTEPs and map a VNI to a corresponding VLAN. As a result, packets belonging to different VLANs are separated in tunnel 130. However, such allocation limits the traffic separation in tunnel 130 to only VLANs. Under such circumstances, other forms of traffic separation may not be available.

To solve this problem, tunnel endpoint 104 can allocate a network identifier based on a locally defined rule. In some embodiments, a network administrator can define such a rule at tunnel endpoint 104 using an access control list (ACL). Such a rule can be based on, but is not limited to, a flow definition, a flow identifier assigned to a flow defined by a flow definition, a source MAC address, a source IP address, an IP subnet, a customer VLAN tag, a global VLAN tag. A flow can be defined based on one or more of: a source MAC address, a destination MAC address, a source IP address, a destination IP address, an ingress port of the tunnel endpoint, and a transport protocol port (e.g., associated with a socket).

Tunnel endpoint 104 stores a respective rule and a corresponding network identifier in an entry in a rule mapping table 144. Tunnel endpoint 104 represents each entry in rule mapping table 144 based on MAC addresses of servers 132 and 134 to generate a network identifier allocation table 146. Network identifier allocation table 146 maps a respective network identifier to one or more corresponding MAC addresses of servers 132 and 134 based on the rule associated with the network identifier. Tunnel endpoint 104 then provides network identifier allocation table 146 to virtualization manager 108.

Upon receiving network identifier allocation table 146, virtualization manager 108 maps the virtual MAC addresses of virtual machines 122, 123, 124, 125, 126, 127, 128, and 129 to corresponding network identifiers based on their respective usage and configuration. Virtualization manager 108 then stores these mappings in a MAC mapping table 148. Suppose that these virtual machines belong to a business entity, and servers 132 and 134 provide two different services to the business entity (e.g., printing service and mail service). If virtual machines 122, 123, 124, and 125 use the service provided by server 132, virtualization manager 108 maps the MAC addresses of virtual machines 122, 123, 124, and 125 to the network identifier mapped to server 132. In the same way, if virtual machines 126, 127, 128, and 129 use the service provided by server 134, virtualization manager 108 maps the MAC addresses of virtual machines 126, 127, 128, and 129 to the network identifier mapped to server 134.

Virtualization manager 108 then sends MAC mapping table 148 to tunnel endpoint 104, which stores MAC mapping table 148 in a local storage device. Tunnel endpoint 104 then updates a local MAC address table 144 based on MAC mapping table 148. These entries can indicate tunnel 106 as the egress interface. It should be noted that one or more entries of MAC address table 144 can also be populated based on layer-2 MAC address learning.

For example, upon learning MAC addresses of servers 132 and 134, tunnel endpoint 104 generates respective entries comprising the MAC addresses of servers 132 and 134 mapping to ports 133 and 135, respectively, as egress ports. Upon identifying a packet with a destination address associated with one of the virtual MAC addresses, tunnel endpoint 104 encapsulates the packet with a tunnel encapsulation header and sends the encapsulated packet via tunnel 108 to tunnel endpoint 102. Tunnel endpoint 102 decapsulates the encapsulation header and forwards the packet to the corresponding virtual machine.

Mapping Tables

FIG. 1B illustrates an exemplary MAC address table facilitating rule-based network identifier mapping for a tunnel, in accordance with an embodiment of the present invention. In this example, MAC address table 142 maps a MAC address and a corresponding VLAN identifier to an interface. Suppose that servers 132 and 134 have MAC addresses 136 and 138, respectively. As described in conjunction with FIG. 1A, upon learning these MAC addresses from interfaces 133 and 135, respectively, tunnel endpoint 104 creates an entry mapping MAC address 136 and its VLAN 110 to interface 133, and another entry mapping MAC address 138 and its VLAN 110 to interface 135.

Similarly, suppose that virtual machines 122, 123, 124, 125, 126, 127, 128, and 129 have MAC addresses 152, 153, 154, 155, 156, 157, 158, and 159, respectively. Based on MAC mapping table 148, tunnel endpoint 104 creates respective entries for MAC addresses 152, 153, 154, 155, 156, 157, 158, and 159. Each of these entries maps the corresponding MAC address and its VLAN 110 to tunnel 108. This allows tunnel endpoint 104 to forward a packet with one of these MAC addresses via tunnel 108.

FIG. 1C illustrates an exemplary rule mapping table facilitating rule-based network identifier mapping for a tunnel, in accordance with an embodiment of the present invention. In this example, rule mapping table 144 maps a respective rule to a corresponding network identifier. As described in conjunction with FIG. 1A, suppose that two rules 172 and 174 are defined for servers 132 and 134, respectively. For example, rules 172 and 174 can specify MAC addresses 136 and 138, respectively, as source addresses. Rule mapping table 144 maps rules 172 and 174 to VNIs 162 and 164, respectively. In some embodiments, rule mapping table 144 further maps sequence numbers 1 and 2 to rules 172 and 174, respectively. These sequence numbers can be rule identifiers and sequentially generated at tunnel endpoint 104. Since MAC addresses 136 and 138 are associated with VLAN 110, rule mapping table 144 can further include rule mapping table 144 can further include VLAN 110.

FIG. 1D illustrates an exemplary network identifier allocation table facilitating rule-based network identifier mapping for a tunnel, in accordance with an embodiment of the present invention. In this example, network identifier allocation table 146 represents a respective rule-to-VNI mapping as one or more MAC address-to-VNI mappings. For example, rules 172 and 174 in rule mapping table 144 correspond to MAC addresses 136 and 138, respectively. Hence, network identifier allocation table 146 maps MAC addresses 136 and 138 to corresponding VNIs 162 and 164, respectively.

Furthermore, since VNIs 162 and 164 are associated with tunnel 106, network identifier allocation table 146 further maps VNIs 162 and 164 to corresponding tunnel 106. In some embodiments, tunnel 106 is identified in network identifier allocation table 146 based on the switch identifiers (e.g., IP addresses) of tunnel endpoints 102 and 104. Since virtualization manager 108 is capable of processing MAC address-to-VNI mapping, virtual manager can generate corresponding mappings for the virtual MAC addresses manages by virtualization manager 108. In this way, rule-based network identifier allocation can be implemented without modifying virtualization manager 108.

FIG. 1E illustrates an exemplary MAC mapping table facilitating rule-based network identifier mapping, in accordance with an embodiment of the present invention. In this example, MAC mapping table 146 maps virtual MAC addresses of virtual machines to corresponding network identifiers based on network identifier allocation table 146. As described in conjunction with FIG. 1A, Since virtual machines 122, 123, 124, and 125 correspond to server 132's MAC address 136, which is mapped to VNI 162, MAC mapping table 148 maps MAC addresses 152, 153, 154, and 155 to VNI 162. In the same way, MAC mapping table 148 maps MAC addresses 156, 157, 158, and 159 to VNI 164. Virtualization manager 108 then provides MAC mapping table 148 to tunnel endpoint 104.

Network of Interconnected Switches

FIG. 2 illustrates an exemplary network of interconnected switched operating as a tunnel endpoint with rule-based network identifier mapping support, in accordance with an embodiment of the present invention. As illustrated in FIG. 2, tunnel endpoint 104 is a switch a network 200, which also includes switches 201, 202, 203, and 205. Network 200 can operate as a single tunnel endpoint for tunnel 106. Here, servers 132 and 134 are coupled to switch 104. In this example, network 130 is coupled to switch 202.

In some embodiments, network 200 is represented as a virtual switch 210 with a virtual MAC address and a virtual IP address. Tunnel endpoint 102 considers virtual switch 210 as the remote tunnel endpoint for tunnel 106 and identifies virtual switch 210 using the virtual IP and/or MAC addresses. For example, tunnel 106 then can be identified using the IP address of tunnel endpoint 102 and the virtual IP address of virtual switch 210. To operate as a single tunnel endpoint, MAC address table 142 and rule mapping table 144 is shared among a respective switch of network 200.

In some embodiments, network 200 is TRILL network and a respective switch in network 200 is a TRILL RBridge. Inter-switch packet forwarding in network 200 can be based on encapsulating an Ethernet packet received from an end device with a TRILL header. In some further embodiments, network 200 is an IP network and a respective switch of network 200, such as switch 104, is an IP-capable switch, which calculates and maintains a local IP routing table (e.g., a routing information base or RIB), and is capable of forwarding packets based on its IP addresses. Under such a scenario, communication among the switches in network 200 is based on IP or IP-based tunneling. Examples of such a tunneling protocol include, but are not limited to, VXLAN, GRE, L2TP, and MPLS.

In some embodiments, network 200 is a fabric switch (under such a scenario, network 200 can also be referred to as fabric switch 200). Fabric switch 200 is identified by and assigned to a fabric switch identifier (e.g., a fabric label). A respective member switch of fabric switch 200 is associated with that fabric switch identifier. This allows the member switch to indicate that it is a member of fabric switch 200. In some embodiments, whenever a new member switch joins fabric switch 200, the fabric switch identifier is associated with that new member switch. Furthermore, a respective member switch of fabric switch 200 is assigned a switch identifier (e.g., an RBridge identifier, a Fibre Channel (FC) domain ID (identifier), or an IP address). This switch identifier identifies the member switch in fabric switch 200. The fabric label can be included in a header of packet for any inter-fabric and/or intra-fabric communication.

Switches in network 200 use edge ports to communicate with end devices (e.g., non-member switches) and inter-switch ports to communicate with other member switches. For example, switch 104 is coupled to server 132 via an edge port (e.g., port 136) and to switches 201, 202, 203, and 205 via inter-switch ports and one or more links. Data communication via an edge port can be based on Ethernet and via an inter-switch port can be based on a fabric encapsulation protocol (e.g., VXLAN or TRILL). It should be noted that control message exchange via inter-switch ports can be based on a different protocol (e.g., the IP or FC protocol).

Suppose that switch 104 receives a packet from server 132 destined to virtual machine 122. This packet can be an Ethernet frame with MAC address 152 as the destination address. Switch 104 determines (e.g., from MAC address table 142) that the packet should be forwarded via tunnel 106. Switch 104 then encapsulates the packet with a fabric encapsulation header that forwards the packet within network 200. Since network 130 is coupled to switch 202, to initiate forwarding via tunnel 106, switch 104 sets the destination address of the fabric encapsulation header to be the switch identifier of switch 202. For example, if network 200 is a TRILL network, the fabric encapsulation header can be a TRILL header, and the destination address of the fabric encapsulation header can be the RBridge identifier of switch 202. Switch 104 then sends the encapsulated packet to switch 202 via network 200.

Upon receiving the encapsulated packet, switch 202 determines that the destination address of the fabric encapsulation header is assigned to the local switch. Switch 202 then decapsulates the fabric encapsulation header to retrieve the inner packet (i.e., the Ethernet frame). Switch 202 determines from MAC address table 142 that MAC address 152 is reachable via tunnel 106. Switch 202 then encapsulates the packet with a tunnel encapsulation header (e.g., a VXLAN header) and assigns VNI 162 in the tunnel encapsulation header from MAC mapping table 148.

Operations

FIG. 3A presents a flowchart illustrating an exemplary process of a tunnel endpoint allocating a network identifier to a rule, in accordance with an embodiment of the present invention. During operation the tunnel endpoint obtains a rule to classify traffic (operation 302) and allocates a network identifier to the obtained rule (operation 304). The tunnel endpoint then creates an entry in the local rule mapping table to map the rule to a corresponding network identifier (operation 306). This network identifier can be provided by a network administrator or generated by the tunnel endpoint (e.g., based on sequential generation). The tunnel endpoint, optionally, incorporates additional information, such as a sequence number and a VLAN identifier, into the mapping (operation 308).

FIG. 3B presents a flowchart illustrating an exemplary process of a tunnel endpoint providing a network identifier allocation table to a virtualization manager, in accordance with an embodiment of the present invention. During operation, the tunnel endpoint expresses a respective rule in the rule mapping table in associated with corresponding local MAC address(es) (e.g., locally learned MAC address(es)) (operation 332). The tunnel endpoint maps a tunnel identifier and a network identifier to a respective local MAC address in a rule mapping table (operation 334). The tunnel endpoint creates a network identifier allocation table (operation 336).

For a respective local MAC address, the tunnel endpoint creates an entry in the network identifier allocation table mapping the local MAC address to a corresponding tunnel identifier and a network identifier (operation 338). The tunnel identifier then generates a control message comprising the network identifier allocation table for a virtualization manager (operation 340). The tunnel endpoint determines an egress port associated with virtualization manager (operation 342) and transmits the control message via the determined egress port (operation 344).

FIG. 3C presents a flowchart illustrating an exemplary process of a tunnel endpoint processing a MAC mapping table received from a virtualization manager, in accordance with an embodiment of the present invention. The tunnel endpoint obtains a MAC mapping table from a notification message from the virtualization manager (operation 352). The tunnel endpoint obtains a mapping between a respective remote MAC address (e.g., a virtual MAC address of a virtual machine) and a corresponding tunnel identifier and network identifier from the MAC mapping table (operation 354). The tunnel endpoint obtains VLAN information associated with a respective remote MAC address from the notification message (operation 356). For a respective remote MAC address, the tunnel endpoint creates an entry in the MAC address table mapping the remote MAC address to a corresponding VLAN identifier and a tunnel identifier (operation 358).

FIG. 4 presents a flowchart illustrating an exemplary process of a tunnel endpoint forwarding a packet, in accordance with an embodiment of the present invention. During operation, the tunnel endpoint receives a packet via a local port (operation 402) and determines a rule associated with the packet based on one or more fields in the packet (operation 404). The tunnel endpoint then determines a network identifier based on the determined rule (operation 406) and identifies a tunnel based on a destination address (e.g., a destination MAC address) of the packet (operation 408).

The tunnel endpoint encapsulates the packet with an encapsulation header associated with the tunnel (operation 410). The tunnel endpoint sets the local and remote tunnel endpoint identifiers (e.g., IP addresses) as source and destination addresses of the encapsulation header respectively. The tunnel endpoint determines an egress port associated with the tunnel (operation 414) and transmits the encapsulated packet via the determines egress port (operation 416).

Exemplary Switch

FIG. 5 illustrates an exemplary tunnel endpoint with rule-based network identifier mapping support for a tunnel, in accordance with an embodiment of the present invention. In this example, a switch 500 includes a number of communication ports 502, a packet processor 510, a tunnel management module 530, a network identifier module 532, a rule management module 520, and a storage device 550. Switch 500 can also include switch modules, such as processing hardware of switch 500 (e.g., ASIC chips). Packet processor 510 extracts and processes header information from the received packets. Packet processor 510 can identify a switch identifier associated with the switch in the header of a packet.

In some embodiments, switch 500 maintains a membership in a fabric switch, as described in conjunction with FIG. 1, wherein switch 500 also includes a fabric switch module 540. Fabric switch module 540 maintains a configuration database in storage device 550 that maintains the configuration state of every switch within the fabric switch. Fabric switch module 540 maintains the state of the fabric switch, which is used to join other switches. In some embodiments, switch 500 can be configured to operate in conjunction with a remote switch as an Ethernet switch.

Communication ports 502 can include inter-switch communication channels for communication within the fabric switch. This inter-switch communication channel can be implemented via a regular communication port and based on any open or proprietary format. Communication ports 502 can also include one or more extension communication ports for communication between neighbor fabric switches. Communication ports 502 can include one or more TRILL ports capable of receiving frames encapsulated in a TRILL header. Communication ports 502 can also include one or more IP ports capable of receiving IP packets. An IP port is capable of receiving an IP packet and can be configured with an IP address. Packet processor 510 can process TRILL-encapsulated frames and/or IP packets (e.g., tunnel encapsulated packets).

During operation, tunnel management module 530 operates switch 500 as a tunnel endpoint and maintains a corresponding tunnel. Rule management module 520 obtains one or more rules. Network identifier management module 532 allocates network identifiers to a respective rule in a rule mapping table. Rule management module 520 can represent the rules based on locally learned MAC addresses and map them to the corresponding network identifier to a generate network identifier allocation table. Network identifier management module 532 obtains the remote MAC address to network identifier mapping from a MAC mapping table and updates a local MAC address table accordingly.

In some embodiments, tunnel management module 530 operates switch 500 as a distributed tunnel endpoint in conjunction with another switch for a plurality of service tunnels. Switch 500 and the other switch are associated with an IP address indicating the distributed tunnel endpoint. Packet processor 510 encapsulates the packet with an encapsulation header and sets the IP address as a source address of the encapsulation header. Tunnel management module 530 can elect a distribution master from switch 500 and the other switch.

Note that the above-mentioned modules can be implemented in hardware as well as in software. In one embodiment, these modules can be embodied in computer-executable instructions stored in a memory which is coupled to one or more processors in switch 500. When executed, these instructions cause the processor(s) to perform the aforementioned functions.

In summary, embodiments of the present invention provide a switch and a method that facilitate rule-based network identifiers for separation of traffic in a tunnel. In one embodiment, the switch includes a storage device, a rule management module, a network identifier module, and a packet processor. During operation, the rule management module determine a rule to classify traffic. The network identifier module then allocates a network identifier associated with a tunnel to the rule and stores a first mapping between the network identifier and a first media access control (MAC) address in the storage device. The first MAC address can be locally learned and represent the rule. The packet processor generates a control packet comprising the first mapping for a virtualization manager of a virtual machine and obtains a second mapping that maps a second MAC address of the virtual machine and an identifier of the tunnel to the network identifier from a notification packet from the virtualization manger.

The methods and processes described herein can be embodied as code and/or data, which can be stored in a computer-readable non-transitory storage medium. When a computer system reads and executes the code and/or data stored on the computer-readable non-transitory storage medium, the computer system performs the methods and processes embodied as data structures and code and stored within the medium.

The methods and processes described herein can be executed by and/or included in hardware modules or apparatus. These modules or apparatus may include, but are not limited to, an application-specific integrated circuit (ASIC) chip, a field-programmable gate array (FPGA), a dedicated or shared processor that executes a particular software module or a piece of code at a particular time, and/or other programmable-logic devices now known or later developed. When the hardware modules or apparatus are activated, they perform the methods and processes included within them.

The foregoing descriptions of embodiments of the present invention have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit this disclosure. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. The scope of the present invention is defined by the appended claims. 

What is claimed is:
 1. A switch, comprising: a storage device; rule management circuitry configured to store, in the storage device, a first mapping that maps a virtual network identifier of a tunnel to a rule for classifying traffic, wherein the virtual network identifier identifies a virtualized network associated with the tunnel; network identifier circuitry configured to: generate, for a virtualization manager of a virtual machine, a control packet comprising a representation of the first mapping for a respective local end device; and obtain, from a notification packet from the virtualization manger, a second mapping that maps the virtual network identifier to an identifier of the virtual machine and an identifier of the tunnel.
 2. The switch of claim 1, wherein the packet processor is further configured to: encapsulate a packet destined to the virtual machine with an encapsulation header; and incorporate the virtual network identifier in the encapsulation header based on the second mapping.
 3. The switch of claim 1, further comprising tunnel management circuitry configured to operate the switch as a tunnel endpoint for the tunnel, wherein the switch is associated with an Internet Protocol (IP) address assigned to the tunnel endpoint.
 4. The switch of claim 3, wherein the tunnel endpoint operates based on a tunneling protocol, and wherein the tunneling protocol is one of: virtual extensible LAN (VXLAN), generic routing encapsulation (GRE), network virtualization using GRE (NVGRE), layer-2 tunneling protocol (L2TP), and multi-protocol label switching (MPLS).
 5. The switch of claim 1, wherein the rule is based on one or more of: a flow definition, a flow identifier assigned to a flow defined by a flow definition, a media access control (MAC) address, an IP address, an IP subnet, a customer VLAN tag, a service VLAN, and a global VLAN tag.
 6. The switch of claim 5, wherein the flow definition identifies a packet belonging to a flow, and wherein the flow definition is based on one or more of: a source MAC address of the packet, a destination MAC address of the packet, a source IP address of the packet, a destination IP address of the packet, an ingress port of the tunnel endpoint, and a transport protocol port.
 7. The switch of claim 1, wherein the switch is a member of a network of interconnected switches, which is identified based on a fabric identifier, wherein the network of interconnected switches operate as a tunnel endpoint for the tunnel.
 8. The switch of claim 1, wherein the virtual network identifier is a VXLAN network identifier (VNI).
 9. A method, comprising: storing, in local a storage device, a first mapping that maps a virtual network identifier of a tunnel to a rule for classifying traffic, wherein the virtual network identifier identifies a virtualized network associated with the tunnel; generating, for a virtualization manager of a virtual machine, a control packet comprising a representation of the first mapping for a respective local end device; and obtaining, from a notification packet from the virtualization manger, a second mapping that maps the virtual network identifier to an identifier of the virtual machine and an identifier of the tunnel.
 10. The method of claim 9, further comprising: encapsulating a packet destined to the virtual machine with an encapsulation header; and incorporating the virtual network identifier in the encapsulation header based on the second mapping.
 11. The method of claim 9, further comprising operating the switch as a tunnel endpoint for the tunnel, wherein the switch is associated with an Internet Protocol (IP) address assigned to the tunnel endpoint.
 12. The method of claim 11, wherein the tunnel endpoint operates based on a tunneling protocol, and wherein the tunneling protocol is one of: virtual extensible LAN (VXLAN), generic routing encapsulation (GRE), network virtualization using GRE (NVGRE), layer-2 tunneling protocol (L2TP), and multi-protocol label switching (MPLS).
 13. The method of claim 9, wherein the rule is based on one or more of: a flow definition, a flow identifier assigned to a flow defined by a flow definition, a media access control (MAC) address, an IP address, an IP subnet, a customer VLAN tag, a service VLAN, and a global VLAN tag.
 14. The method of claim 13, wherein the flow definition identifies a packet belonging to a flow, and wherein the flow definition is based on one or more of: a source MAC address of the packet, a destination MAC address of the packet, a source IP address of the packet, a destination IP address of the packet, an ingress port of the tunnel endpoint, and a transport protocol port.
 15. The method of claim 9, wherein the switch is a member of a network of interconnected switches, which is identified based on a fabric identifier, wherein the network of interconnected switches operate as a tunnel endpoint for the tunnel.
 16. The method of claim 9, wherein the virtual network identifier is a VXLAN network identifier (VNI).
 17. A computer system; comprising: a storage device; a processor; and a non-transitory computer-readable storage medium storing instructions which when executed by the processor causes the processor to perform a method, the method comprising: storing, in the storage device, a first mapping that maps a virtual network identifier of a tunnel to a rule for classifying traffic, wherein the virtual network identifier identifies a virtualized network associated with the tunnel; generating, for a virtualization manager of a virtual machine, a control packet comprising a representation of the first mapping for a respective local end device; and obtaining, from a notification packet from the virtualization manger, a second mapping that maps the virtual network identifier to an identifier of the virtual machine and an identifier of the tunnel.
 18. The computer system of claim 17, wherein the method further comprises: encapsulating a packet destined to the virtual machine with an encapsulation header; and incorporating the virtual network identifier in the encapsulation header based on the second mapping.
 19. The computer system of claim 18, wherein the method further comprises operating the switch as a tunnel endpoint for the tunnel, wherein the switch is associated with an Internet Protocol (IP) address assigned to the tunnel endpoint.
 20. The computer system of claim 18, wherein the rule is based on one or more of: a flow definition, a flow identifier assigned to a flow defined by a flow definition, a source MAC address, a source IP address, an IP subnet, a customer virtual area network (VLAN) tag, and a global VLAN tag. 